This invention relates, in general, to semiconductor devices, and more particularly, to insulated gate field effect transistors for low power applications.
Semiconductor devices such as insulated gate field effect transistors (IGFETs) are becoming increasingly important in low voltage applications. As IGFET devices are scaled to smaller and smaller dimensions, manufacturers must refine transistor designs to maintain optimum device performance. These performance considerations include power consumption, leakage current, reliability during operation, breakdown voltage, etc.
One significant performance consideration is the relatively high current consumption as the result of charging and discharging power supply lines. During operation, the parasitic capacitance characteristic of the power supply lines becomes a limiting factor in the maximum frequency that a transistor can operate at. One previously known attempt at addressing this limitation places discrete capacitors in parallel with the power supply lines to increase the amount of charge that is available at the instant a transistor conducts. However, this alternative is not practical in a high volume manufacturing operation due to the expense and reliability issues associated with discrete capacitors.
Accordingly, a need exists to provide a semiconductor device that has improved performance characteristics and is more reliable than devices known in the art.